Estimation of halogens:
Carisu Method: A known mass of compound is heated with conc. `HNO_(3)` in the presence of `AgNO_(3)` contained in a hard glass tube known as carius tube in a furnce. C and H are oxidised to `CO_(2)` and `H_(2)O` . The halogen forms the corresponding AgX. It is filtered , dried , and weighed.
Estimation of sulphur: A known mass of compound is heated with fuming `HNO_(3)` or sodium peroxide `(Na_(2)O_(2))` in the presence of `BaCl_(2)` solution in Carius tube. Sulphur is oxidised to `H_(2)SO_(4)` and precipitated as `BaSO_(4)` . It is filerted, dried and weighed.
0.32 gm of an organic substance when treated by Carius method gave 0.466 gm of `BaSO_(4)` . Calculate the percentage of sulphur in the compound (Ba=137)
A. `10.0`
B. `34.0`
C. `20.0`
D. `30.0`
